Podoplanin expression in human tooth germ tissues and cystic odontogenic lesions: an immunohistochemical study

J Oral Pathol Med (2010) 39: 115–120 Background: Podoplanin expression was described in mouse tooth germ and apical bud cells. The aim of this study was to analyse the podoplanin expression of human tooth germ tissues, adult teeth and odontogenic lesions immunohistochemically. Study Design: Nine human tooth germ biopsies and seven healthy permanent teeth extracted for orthodontic reasons were examined. Anti‐podoplanin (D2‐40) reactivity was investigated immunohistochemically. Five well‐defined cystic odontogenic lesions (10 radicular cysts, 10 follicular cysts, three keratocystic odontogenic tumours, five ameloblastomas, and two adenomatoid odontogenic tumours) were analysed simultaneously. Results: Podoplanin expression was detected in the majority of epithelial and ecto‐mesenchymal cells of human tooth germ tissues, odontoblasts and superficial dental pulp fibroblasts of permanent teeth. Cystic odontogenic lesions revealed positive reactions predominantly at the invasion front edge within basal epithelial layers. Conclusion: Podoplanin appears to be involved in the orthologic and pathologic processes of the formation of elongated cell extensions and odontoblastic fibers, in the epithelial–mesenchymal transition and local invasion during tooth germ development as well as in both reactive and neoplastic odontogenic cystic lesions.